1. Field of the Invention
This application relates to the field of wireless data communication networks, and more particularly to the field of energy conservation in such wireless networks.
2. Description of Related Art
An ad hoc network is one in which all of the communicating stations organize themselves into a single communications fabric. The network adapts to changes such as movement of stations, destruction of stations, addition of new stations, signal interference, and the like. Ad hoc network techniques, such as packet radio, actually pre-date more generally known data networks such as the Internet. However, current ad hoc networks are typically designed to carry Internet Protocol (xe2x80x9cIPxe2x80x9d) traffic.
Network protocols, such as IP, provide for addressing, error detection and correction, message ordering, and other network functions. These network functions are typically provided in a network layer, which operates between higher layers such as an application layer, and lower layers, for example, a physical layer. Thus the application layer may communicate with remote applications through the network layer without tending to details of how error-free communication is achieved. The network layer, in turn, can provide network functionality without tending to the details associated with a physical link, such as modulation schemes.
The existence of known network protocols simplifies the design of ad hoc networks by providing well known techniques for implementing standardized network layer functionality and interfaces. An additional network layer is typically provided in ad hoc networks to manage link changes and network volatility. However, as a significant disadvantage, these network protocols are insensitive to issues of energy conservation, a design constraint of some importance in mobile networking environments where mobile stations generally operate from a battery with limited energy capacity.
There remains a need for a network protocol that improves energy efficiency in a mobile network.
According to the principles of the invention, there is provided a system, apparatus, and method for conserving energy in a mobile station of an ad hoc wireless data network. Information concerning motion of the mobile station is obtained, and a rate of motion is used to adjust network parameters such as a beaconing rate and a sensitivity to link quality changes. These parameters may be adjusted to reduce network overhead transmissions, and the power usage associated therewith, at appropriate times. In one embodiment, network-related transmissions, such as beacon signals and link state announcements, are reduced when the mobile station is moving quickly.
A method for conserving energy in a mobile station of a wireless ad hoc network is described, including determining a motion rate of the mobile station, and adjusting one or more network parameters of the mobile station in response to a change in the motion rate. In one embodiment, each of the one or more network parameters is associated with an amount of network overhead traffic originating from the mobile station.
A computer program product for conserving energy in a mobile station of a wireless ad hoc network is also provided, including computer executable code that determines a motion rate of the mobile station, and computer executable code that adjusts one or more network parameters of the mobile station in response to a change in the motion rate. In one embodiment, each of the one or more network parameters is associated with an amount of network overhead traffic originating from the mobile station.
In another aspect, a mobile station for use in an energy conserving wireless ad hoc network is described, including a motion data source, the motion data source providing a motion data signal describing motion of the mobile station, and a network control, the network control managing a connection to an ad hoc wireless data network. The network control receives the motion data signal and uses the motion data signal to determine one or more network parameters. In one embodiment, each of the one or more network parameters is associated with an amount of network overhead traffic originating from the mobile station.
In another aspect, a network control for conserving energy in a mobile station of a wireless ad hoc network is described. The network control manages a connection to an ad hoc wireless data network. The network control receives a motion data signal relating to the motion of the mobile station and the network control using the motion data signal to determine one or more network parameters. In one embodiment, each of the one or more network parameters is associated with an amount of network overhead traffic originating from the mobile station.